The product , which costs between $36.95 and $50.99 at various online retailers, is straightforward enoughit comes in a small box which contains an eight-page quick start guide, a software CD, a USB cable, a phone cable, and the adapter itself, which is about the size of a deck of playing cards (4" x 3" x 3/4").

The installation process is pretty straightforward: With Skype running on your computer (under Windows XP, 2000 or Vista only), you insert the CD into your CD-ROM drive and it self-installs. You select your language from an impressively broad range of options (not only English, Spanish, and French, but Polish, Turkish, Vietnamese, and many more), click on 'Install Drivers,' then follow the Windows Setup Wizard.

Hooking up the adapter
When the install is finished, you're prompted to connect the adapter to your PC's USB port. Upon connection, a pop-up window appears in your Skype application asking for permission to allow ZoomAgent.exe to access Skype. Accepting that request ends the installation, and a small green Zoom Technologies telephone icon appears on your taskbar.

At this point, it gets a little confusing. You're prompted to plug a corded or cordless phone into the phone connector on the Model 5900 Phone Adapterand then, as the manual states, "Now you can start making calls via Skype and Zoom Phone Adapter." But how? To find out more, the next step is to go to back to the installation CD and open the Documentation Folder, which contains the full 33-page PDF manual.

As the manual indicates, an optional additional step that allows you to make both Skype and non-Skype calls from the same phone is to connect the adapter's LINE jack to a standard telephone wall jack. And then, to verify your connection, you simply click the 'Skype Test Call' option on the Skype Contacts tab and record and listen to a message on your handsetsimple enoughand in my testing, it worked perfectly the first time.

Basic calling
With these steps out of the way, you're ready to make calls. The adapter itself has three LEDs on its front panel: a power light, a TELCO light, and a VOIP light. Logically enough, when you make a landline call, the TELCO light is lit, and when you make a Skype call, the VOIP light is lit. (Between calls, if it's plugged into a wall jack, it also seems to default to keeping the TELCO light lit.)

To place a landline call, you just pick up the phone and dial as usual. To make a Skype call, you can either dial from the Skype Contacts tab on your PC, or you can set up a speed dial number for the contact within Skype and then dial it directly from your handset by entering ##, the speed dial number, and *.

Want to use Skype to save money on international calls? Dial ##00, the country code and phone number, and *. Again, all of these functions worked perfectly the first time I tried them.

According to the manual, you can also switch between Skype and landline calls by dialing #1so if you're on a landline call and a Skype call comes in, hitting #1 will put the landline call on hold and answer the Skype call. To switch back to the first call, hit #1 again. If you want to drop one call for another instead of putting the first call on hold, just hit ## instead of #1. And if you want to do three-way calling, hit #2 to conference two calls together.

Advanced functionality
It sounds greatand it isbut in action, it's a bit more limited than that. When I tested it by initiating a Skype call and trying to switch over to an incoming landline call by dialing #1, it didn't workI dialed #1 and nothing happened. Dialing ## did work, though, terminating the Skype call and switching me over to the landline call. A second test had the same result: #1 didn't worked at all, but ## worked immediately.
The box promises a wide range of additional functionality as well. You can forward landline calls to Skype, either instantly or after a specific number of rings; you can enable answering machine functionality within the Model 5900 Phone Adapter (messages are stored on your computer); and you can access your Skype account by calling into your landline number from a remote landline or cell phone (a feature known as toll bypass).

To enable the answering machine, you simply select a checkbox in the interface that tells the adapter to answer after a specific number of rings, and it does so. According to the manual, you'll hear a stuttering dial tone to tell you that a message is waiting.

In my case, the answering machine worked fine, at least in terms of answering incoming callsbut when I left a test message, I didn't get the stuttering dial tone as a message-waiting indicator. I was able to find the message as a WAV file on my PC, but if I hadn't looked for it, I would never have known it was there. And while the manual says that dialing * on the handset will give you access to the voicemail system to change your outgoing message and listen to voicemails, nothing at all happened when I dialed *. (Calling in from another phone and interrupting the outgoing message by dialing *, though, did work.)

Conclusion
Despite the rough edges on voicemail and call transfer, other functions, like toll bypass, worked fine (making it a great way to place cheap international calls from your cell phone as long as you're willing to leave your PC on at all times), and the ability to start both landline and Skype calls simply by dialing from the same phone was seamlesspick up the phone and dial, and you get landline; pick up the phone and dial a Skype speed dial code, and you're on Skype.

So while Zoom may have some kinks to work out on more advanced functions like three-way calling and voicemail, the Model 5900 Phone Adapter seems to be a solid option (though, admittedly, just one of many) for making Skype a more integral part of your home phone system.